Wood-pulp-grinding machine.



- PATENTED MAY 5,l903.

G. SGHMITIHENNER. WOOD PULP I GRINDING MACHINE.

APPLICATION FILED FEB. 17, 1903.

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- Ur'rnn STATES Patented May 5, 1903.

PATENT OFFICE.

CARLOS SCI-IMITTHENNER, OF HEIDENHEIM, GERMANY, ASSIGN OR TO J. M. VOITH, OF HEIDENHEIM, GERMANY, 'A FIRM.

wooo-ruLP-cnmome MACHINE.

SPECIFICATION formingpart of Letters Patent No. 727,458, dated May 5, 1903. Application filed February 17,1903. Serial No- 145,833. (No model.)

To all whom it may concern.-

Beit known that I, OARLos SCHMITTHENNER, a citizen of the Empire of Germany, residing in Heidenheim-on-the-Brenz, in the Kingdom of Wiirtemburg, in the Empire of Germany,

have invented certain new and useful Improvements in \Vood-Grinding Machines, of which the following is a specification.

This invention relates to a wood-grinding machine in which a plurality of feed-pockets provided with pressure-cylinders are disposed around the periphery of a grinding-stone for feeding the wood to be ground by hydraulic or other fluid pressure.

The object of the invention is to provide simple automatic mechanism for controlling the pressure of the feed-cylinders, so as to maintain a uniform action of the rotary grinder during the variations of load, due to the cutting outof one or more of the feedcylinders.

Figure 1 of the accompanying drawings represents a side elevation of one form of wood-grinding machine embodying this invention. Fig. 2 represents alongitudinal section of one of the feed-cylinders in operative connection with the grindstone.

The same reference characters indicate corresponding parts in both figures.

This invention is embodied in a wood-pulpgrinding machine comprising the usual elements of such an apparatusto wit, a rotary grinder E on a shaft F, which receives motion from driving mechanism,(notshown;) anumber of pockets P for containing the Wood to be ground disposed around the periphery of said grinder and having their inner ends open thereto; pressurecylinders A, attached to the outer ends of said pockets; pushers in said pockets connected, respectively, by piston-rods C with pistons B in said pressurecylinders; a pressure-accumulator L, connected with the source of supply for supplying fluid-pressure to said pressure-cylinders; a pump M for maintaining a standard pressure in said accumulator, and pipes connecting said accumulator with the pressure-cylinders.

In this machine there are two systems of' supply-pipes connecting the pressure-accumulator with the pressure-cylinders, one systern for supplying pressure behind the pistons to effect the feeding and another system for supplying pressure in front of the pistons for retracting the plungers for reloading or repairing. In the working pressure system the pressure is regulated by a governor controlled by the speed of the rotary grinder, and in the retracting pressure system the full pressure of the pressure-accumulator is supplied when required to the pressure-cylinders. The pressure in the accumulator L is maintained at a certain maximum standard by means of a pump M and a safety-valve S. This pressureis in excess of that required to cause the working of all the pockets. Each of the pressure-cylinders A is provided with two valve-chests e and b, the valve-chest e serving to admit water or other fluid under pressure to the outer end of the pressure-cylinder A behind the piston B for the purpose of forcing the wood in contact with the rotary grinder for the working operation and the valve-chest I) being adapted to admit fluidpressure to the inner end of the pressure-cylinder in front of thepiston B for the purpose of retracting the plunger when the pocket is to be refilled or for other purpose. A valve V controls the inlet and exhaust through the valve-chest b, and a valve 1) controls the inlet and exhaust through the valve-chest e, and an actuating rod y is connected to both said valves and actuated by an exterior lever V, so as to move the valves in unison. A system of pipes at connects the pressure-accumulator L with the valve-chest b, and a system of pipes 01 connects said accumulator directly or indirectly with the valve-chest e.

A throttle-valve K is disposed in the pipesystem d, so as to reduce the pressure therein below the normal pressure of the system a.

A governor I is disposed adjacent to the throttle-valve K, and the actuating -lever thereof is connected with said governor, whereby the thr0ttle-valve may be opened and closed automatically. A belt H connects the governor with a pulley G on theshaft F of the rotary grinder E, whereby any variation in the speed of the grinder may beimparted to said governor, which in turn controls the throttle-valve K, and thereby regulates the pressure of the pistons B.

In the use of a grinding-machine provided with this improvement a pressure is maintained in the accumulator L in excess of that required for working all the pressure-cyl- V li-nder Aand to shift valve v so as to openthe supply from the pipes a to the opposite end of the cylinder. The plunger d is thus retracted, and the cutting out of one of the cylinders A tends to reduce the aggregate pressure'upon the grinder and cause it to rorate at a higher speed. Any increase of speed in the grinder immediately raises the governor I, which opens the throttle-valve K, so that an increase of pressure is supplied to the pipe system cl from the accumulator L. This increase of pressure in the pipes doperates to increase the pressure of the pressure-cylin ders remaining in action and restores the aggregate pressure on the grinder, whereby the speed of the latter is reduced to normal.

I claim as my invention-- In a Wood-grinding machine the combination of a rotary grinder, feed-pockets disposed around said grinder, pressure-cylinders for operating said feed-pockets, each provided with two valve-chests connected respectively with the inner and outer ends of said cylinders, a system of pipes connecting the fluidpressure source with the inner valve-chests, valves in said valve-chests, a system of pipes connecting said source with the outer valvechests, means for maintaining an excess of pressure for the inner pipe system, a reducing-valve for the outer system, a governor connecting said reducing-valve and means connecting said governor with the driving mechanism of the rotary grinder.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CARLOS SOI-IMITTHENNER. Witnesses:

ERNEST ENTENMAN, WM. HAHN. 

